Initial implementation of batched request operations

AFNetworking/AFHTTPClient.h

@@ -298,6 +298,34 @@ extern NSString * AFQueryStringFromParametersWithEncoding(NSDictionary *paramete
  */
 - (void)cancelHTTPOperationsWithMethod:(NSString *)method andURL:(NSURL *)url;
 
+///---------------------------------------
+/// @name Batching HTTP Request Operations
+///---------------------------------------
+
+/**
+ Creates and enqueues an `AFHTTPRequestOperation` to the HTTP client's operation queue for each specified request object into a batch. When each request operation finishes, the specified progress block is executed, until all of the request operations have finished, at which point the completion block also executes.
+ 
+ @param requests The `NSURLRequest` objects used to create and enqueue operations.
+ @param progressBlock A block object to be executed upon the completion of each request operation in the batch. This block has no return value and takes two arguments: the number of operations that have already finished execution, and the total number of operations.
+ @param completionBlock A block object to be executed upon the completion of all of the request operations in the batch. This block has no return value and takes a single argument: the batched request operations. 
+ 
+ @discussion Operations are created by passing the specified `NSURLRequest` objects in `requests`, using `-HTTPRequestOperationWithRequest:success:failure:`, with `nil` for both the `success` and `failure` parameters.
+ */
+- (void)enqueueBatchOfHTTPRequestOperationsWithRequests:(NSArray *)requests 
+                                          progressBlock:(void (^)(NSUInteger numberOfCompletedOperations, NSUInteger totalNumberOfOperations))progressBlock 
+                                        completionBlock:(void (^)(NSArray *operations))completionBlock;
+
+/**
+ Enqueues the specified request operations into a batch. When each request operation finishes, the specified progress block is executed, until all of the request operations have finished, at which point the completion block also executes.
+ 
+ @param operations The request operations used to be batched and enqueued.
+ @param progressBlock A block object to be executed upon the completion of each request operation in the batch. This block has no return value and takes two arguments: the number of operations that have already finished execution, and the total number of operations.
+ @param completionBlock A block object to be executed upon the completion of all of the request operations in the batch. This block has no return value and takes a single argument: the batched request operations. 
+ */
+- (void)enqueueBatchOfHTTPRequestOperations:(NSArray *)operations 
+                              progressBlock:(void (^)(NSUInteger numberOfCompletedOperations, NSUInteger totalNumberOfOperations))progressBlock 
+                            completionBlock:(void (^)(NSArray *operations))completionBlock;
+
 ///---------------------------
 /// @name Making HTTP Requests
 ///---------------------------

AFNetworking/AFHTTPClient.m

@@ -49,6 +49,8 @@ static NSString * const kAFMultipartFormBoundary = @"Boundary+0xAbCdEfGbOuNdArY"
 
 #pragma mark -
 
+typedef void (^_AFCompletionBlock)(void);
+
 static NSUInteger const kAFHTTPClientDefaultMaxConcurrentOperationCount = 4;
 
 static NSString * AFBase64EncodedStringFromString(NSString *string) {
@@ -335,6 +337,50 @@ static NSString * AFPropertyListStringFromParameters(NSDictionary *parameters) {
     }
 }
 
+- (void)enqueueBatchOfHTTPRequestOperationsWithRequests:(NSArray *)requests 
+                                          progressBlock:(void (^)(NSUInteger numberOfCompletedOperations, NSUInteger totalNumberOfOperations))progressBlock 
+                                        completionBlock:(void (^)(NSArray *operations))completionBlock
+{
+    NSMutableArray *mutableOperations = [NSMutableArray array];
+    for (NSURLRequest *request in requests) {
+        AFHTTPRequestOperation *operation = [self HTTPRequestOperationWithRequest:request success:nil failure:nil];
+        [mutableOperations addObject:operation];
+    }
+    
+    [self enqueueBatchOfHTTPRequestOperations:mutableOperations progressBlock:progressBlock completionBlock:completionBlock];
+}
+
+- (void)enqueueBatchOfHTTPRequestOperations:(NSArray *)operations 
+                              progressBlock:(void (^)(NSUInteger numberOfCompletedOperations, NSUInteger totalNumberOfOperations))progressBlock 
+                            completionBlock:(void (^)(NSArray *operations))completionBlock
+{
+    NSBlockOperation *batchedOperation = [NSBlockOperation blockOperationWithBlock:^{
+        if (completionBlock) {
+            completionBlock(operations);
+        }
+    }];
+    
+    [self.operationQueue addOperation:batchedOperation];
+    
+    NSPredicate *finishedOperationPredicate = [NSPredicate predicateWithFormat:@"isFinished == YES"];
+    
+    for (AFHTTPRequestOperation *operation in operations) {
+        _AFCompletionBlock originalCompletionBlock = [[operation.completionBlock copy] autorelease];
+        operation.completionBlock = ^{
+            if (progressBlock) {
+                progressBlock([[batchedOperation.dependencies filteredArrayUsingPredicate:finishedOperationPredicate] count], [batchedOperation.dependencies count]);
+            }
+            
+            if (originalCompletionBlock) {
+                originalCompletionBlock();
+            }
+        };
+        
+        [batchedOperation addDependency:operation];
+        [self enqueueHTTPRequestOperation:operation];
+    }
+}
+
 #pragma mark -
 
 - (void)getPath:(NSString *)path